Antineoplastic effects of cassava-cyanide extract on human glioblastoma (LN229) cells

Several natural compounds reduce tumour cell growth and metastasis by inducing programmed cell death. Cassava (Manihot esculentaCrantz) contains cyanogenic glycosides such as, linamarin and lotaustralin, can be enzymatically cleaved by linamarase to release hydrogen cyanide (HCN), which can have therapeutic benefits against hypertension, asthma, and cancer. We have developed a technology for isolatingbio-active principles from cassava leaves.The present study is designed to analyzethe cytotoxic effect of cassava cyanideextract (CCE) against human glioblastoma cells (LN229). The treatment of CCE demonstrated a dose dependent toxicity on glioblastoma cells. At higher concentration tested, the CCE (400  μg/mL) was found to be cytotoxic, reducing the cell viability to 14.07 ± 2.15% by negatively influencing the mitochondrial activity, and lysosomal and cytoskeletal integrity. Coomassie's brilliant blue staining confirmed cells' morphological aberration after 24 h of treatment with CCE. Moreover, DCFH-DA assay and Griess reagent showed an increase in ROS but a decrease in RNS production at a concentration of CCE. Flow cytometry analysis revealed that CCE interfered with G0/G1, S, and G2/M stages of the cell cycle of glioblastoma, and Annexin/PI staining indicated a dose-dependent increase in cell death, confirming the toxic nature of CCE on LN229 cells. These findings suggest that cassava cyanide extract has potential as an antineoplastic agent against glioblastoma cells, which is an aggressive and difficult-to-treat type of brain cancer. However, it is important to note that the study was conducted in vitro, and further research is necessary to assess the safety and efficacy of CCE in vivo. Additionally, it is essential to establish the optimal dose and potential side effects before considering its use as a therapeutic agent.

L-Cysteine capped zinc oxide nanoparticles induced cellular response on adenocarcinomic human alveolar basal epithelial cells using a conventional and organ-on-a-chip approach

Zinc oxide nanoparticles (ZnO NPs) are among the well-characterized nanomaterials with multifaceted biomedical applications, including biomedical imaging, drug delivery, and pharmaceutical preparations. The high surface charge of ZnO NPs leads to the agglomeration of the particles. Therefore, surface coating with a suitable ligand can increase colloidal stability. In this present study, in-vitro responses of ZnO NPs capped with a sulfur-containing amino acid, L-cysteine (Cys-ZnO NPs), on A549 cells was investigated. Fourier Transform Infrared Spectroscopy (FTIR) studies were carried out to confirm the capping of ZnO NPs with L-cysteine. Cytotoxic studies using A549 cells demonstrated reduced cytotoxicity in comparison with already reported pristine Zinc Oxide nanoparticles. The cellular uptake is confirmed by fluorescent cytometry. However, a higher concentration (160 µg/mL) of Cys-ZnO NPs led to apoptotic cell death marked by nuclear condensation, mitochondrial membrane depolarization, actin filament condensation, lysosomal damage LDH leakage, intracellular ROS production, blebbing, upregulation of Bax and downregulation of Bcl-2 gene expression. Cys-ZnO NPs treatment was also carried out in cells cultured in a microfluidic lung-on-a-chip device under a physiologically relevant flow rate. The study concluded that the microfluidic-based lung-on-a-chip culture resulted in reduced cell death compared to the conventional condition.

Effect of cyanide ions (CN-) extracted from cassava (Manihotesculenta Crantz) on Alveolar Epithelial Cells (A549 cells)

Cassava (Manihotesculenta Crantz) is one of the most important root crops in tropical countries. It is a major source of cyanogenic glycosides viz. linamarin and lotaustralin, and these on breakdown liberate HCN and ketone. Cassava cyanide extract (CCE) from cassava leaves and tuber rinds were formulated as a biopesticide against certain borer insect pests of horticultural crops. Adenocarcinomic human alveolar basal epithelial cells (A549) were treated with three different concentrations (100, 200, 400 ppm) of CCE. The MTT and NRU assays showed dose-dependent cytotoxicity. The DCFH-DA assay does not show any free radical scavenging activity, whereas the NRR assay showed a reduction in the nitrile radicals with an increase in the concentration of the bioactive compound. A negative correlation was found between the concentration of the bioactive principles and mitochondrial and lysosomal functions. Various cellular assays demonstrated the cellular response of the CCE, and it was found that at higher concentration (400 ppm), the CCE exert a significant necrotic cell death rather than apoptosis. The results of the study indicated that the CCE have a remarkable tendency of anti-proliferative ability.

Microfluidic synthesis of gelatin nanoparticles conjugated with nitrogen-doped carbon dots and associated cellular response on A549 cells

Gelatin nanoparticles are a versatile class of nanoparticles with wide applications, especially in drug delivery and gene delivery. The inherent biocompatible nature of gelatin and various functional groups can improve the cellular interactions and enhance the efficacy of different drug formulations. Microfluidic hydrodynamic flow-focusing techniques can be used for the synthesis of gelatin nanoparticles. The present work syntheses nitrogen-doped carbon dots conjugated with gelatin nanoparticles (NQD-GNPs) using a microfluidic approach and associated cellular response through various assays. MTT, neutral red uptake, and Calcein AM/Propidium iodide (PI) assays independently proved the biocompatible nature of NQD-GNPs. The NQD-GNPs treatment demonstrated a slight increase in reactive nitrogen species generation and lactate dehydrogenase release. However, it does not alter the mitochondrial membrane potential or lysosomal stability. The cellular uptake of NQD-GNP depends on the concentration and does not affect the apoptotic pathway of the cells. Most of the cells remained viable even after treatment with high concentrations of NQD-GNPs.

Cascade of immune mechanism and consequences of inflammatory disorders

Inflammatory responses arise as an outcome of tissues or organs exposure towards harmful stimuli like injury, toxic chemicals or pathogenic microorganism. It is a complex cascade of immune mechanism to overcome from tissue injury and to initiate the healing process by recruiting various immune cells, chemical mediators such as the vasoactive peptides and amines, pro-inflammatory cytokines, eicosanoids and acute-phase proteins to prevent tissue damage and ultimately complete restoration of the tissue function. The cytokines exhibits a central function in communication between the cells, inflammatory response initiation, amplification and their regulation. This review covers the importance of inflammatory responses; the significance of cytokines in inflammation and numerous inflammatory disorders/ailments due to the abrupt expression of cytokines and the hyper-inflammatory response or cytokine storm associated with poor prognosis in COVID-19 pandemic. Also highlighting the importance of naturally derived anti-inflammatory metabolites to overcome the side-effects of currently prevailing anti-inflammatory drugs.

Comprehensive Development in Organ-On-A-Chip Technology

The expeditious advancement in the organ on chip technology provided a phase change to the conventional in vitro tests used to evaluate absorption, distribution, metabolism, excretion (ADME) studies and toxicity assessments. The demand for an accurate predictive model for assessing toxicity and reducing the potential risk factors became the prime area of any drug delivery process. Researchers around the globe are welcoming the incorporation of organ-on-a-chips for ADME and toxicity evaluation. Organ-on-a-chip (OOC) is an interdisciplinary technology that evolved as a contemporary in vitro model for the pharmacokinetics and pharmacodynamics (PK-PD) studies of a proposed drug candidate in the pre-clinical phases of drug development. The OOC provides a platform that mimics the physiological functions occurring in the human body. The precise flow control systems and the rapid sample processing makes OOC more advanced than the conventional two-dimensional (2D) culture systems. The integration of various organs as in the multi organs-on-a-chip provides more significant ideas about the time and dose dependant effects occurring in the body when a new drug molecule is administered as part of the pre-clinical times. This review outlines the comprehensive development in the organ-on-a-chip technology, various OOC models and its drug development applications, toxicity evaluation and efficacy studies.

Reversal of propranolol blockade of adrenergic receptors and related toxicity with drugs that increase cyclic AMP

An overdose of propranolol, a widely used nonselective beta-adrenergic receptor blocking agent, can result in hypotension and bradycardia leading to irreversible shock and death. In addition, the blockade of adrenergic receptors can lead to alterations in neurotransmitter receptors resulting in the interruption of the activity of other second messengers and the ultimate cellular responses. In the present experiment, three agents, aminophylline, amrinone, and forskolin were tested in an attempt to reverse the potential lethal effects of a propranolol overdose in dogs. Twenty-two anesthetized beagle dogs were given a 10-min infusion of propranolol at a dose of 1 mg/kg/min. Six of the dogs, treated only with intravenous saline, served as controls. Within 15-30 min all six control dogs exhibited profound hypotension and severe bradycardia that led to cardiogenic shock and death. Seven dogs were treated with intravenous aminophylline 20 mg/kg 5 min after the end of the propranolol infusion. Within 10-15 min heart rate and systemic arterial blood pressure returned to near control levels, and all seven dogs survived. Intravenous amrinone (2-3 mg/kg) given to five dogs, and forskolin (1-2 mg/kg) given to four dogs, also increased heart rate and systemic arterial blood pressure but the recovery of these parameters was appreciably slower than that seen with aminophylline. All of these animals also survived with no apparent adverse effects. Histopathologic evaluation of the hearts of the dogs treated with aminophylline showed less damage (vacuolization, inflammation, hemorrhage) than the hearts from animals given propranolol alone. Results of this study showed that these three drugs, all of which increase cyclic AMP, are capable of reversing the otherwise lethal effects of a propranolol overdose in dogs.

Naftazone reduces glutamate cerebro spinal fluid levels in rats and glutamate release from mouse cerebellum synaptosomes

It is well known that an excessive release of glutamate in the mammalian brain plays a major role in several neurological diseases. Naftazone (Etioven) is a currently used vasoprotectant drug that is metabolized in humans by reduction and glucuronidation. In the present study naftazone was found to decrease glutamate levels in the cerebro spinal fluid (CSF) of rats treated for 15 days, as determined by a chemiluminescent glutamate assay reaction. Naftazone and its glucuronide derivative also reduced respectively spontaneous and high K+-evoked glutamate release from mouse cerebellum synaptosomes. It is likely that naftazone and its glucuronide metabolite contribute in vivo to decrease glutamate levels in the CSF through their inhibitory actions on glutamate release.

Reversal of acute theophylline toxicity by calcium channel blockers in dogs and rats

Theophylline, widely used in the treatment of pulmonary diseases, has a narrow therapeutic index; the recommended plasma levels being 10-20 micrograms/ml in humans. The misuse or abuse of theophylline can cause life-threatening central nervous system and cardiovascular effects. Increased intracellular Ca2+ levels are thought to play an important role in theophylline toxicity and death. The objective of this study was to determine whether Ca2+ channel blockers, e.g. verapamil, nifedipine, or diltiazem, prevent sudden death caused by theophylline treatment in rats and dogs. Groups of Sprague-Dawley rats were treated with theophylline alone (150 mg/kg i.p.) or with theophylline pretreatment followed by administration of verapamil (0.25 to 0.5 mg/kg i.p.), nifedipine (0.25 to 1.0 mg/kg i.p.), or diltiazem (0.5 to 1.0 mg/kg i.p.), 2.5 to 15 min later. The rats were observed for toxic signs and survival over a period of 15 days. All three calcium channel blockers significantly reduced the theophylline-induced sudden death in rats. In a separate study, neither verapamil (0.5 mg/kg i.p.) nor nifedipine (1.0 mg/kg i.p.) prevented the theophylline-induced myocardial necrosis in the rat. In beagle dogs, verapamil (0.5 mg/kg i.v.) prevented theophylline (15 mg/kg/min i.v. for 10 min)-induced hypotension, arrhythmias, and sudden death. Our results support previously reported findings that calcium plays a major role in theophylline-induced toxicity and death.

Enhancement of acute myocardial lesions by asthma drugs in rats

Asthma morbidity and mortality have risen significantly in the last 10 years. The reasons for the increase are multifactorial. One proposed explanation is possible myocardial toxicity arising from the use of beta-agonists alone or in combination with methylxanthines. Previous studies have shown that beta-agonists given alone and beta-agonist/methylxanthine combinations given at higher than recommended clinical doses induced dose-related cardiotoxicity and sudden death in rats. The objective of the present study was to determine whether or not beta-agonists given alone and in combination with methylxanthines at recommended clinical doses also induce cardiotoxicity and sudden death in rats. The beta-agonists, isoproterenol hydrochloride (15 micrograms/kg), fenoterol hydrobromide (40 micrograms/kg), and terbutaline hemisulfate (0.4 mg/kg) were given in single sc doses separately and concurrently with the methylxanthines aminophylline hydrate (20 mg/kg) and caffeine (40 mg/kg), which were given up to a susceptible animal model, the heavy Sprague-Dawley rat. beta-agonist-induced myocardial toxicity (necrosis) was observed. The toxicity was enhanced by aminophylline resulting in the sudden death (most likely due to ventricular fibrillation) of some animals. A decrease in serum iron levels was observed in rats of all beta-agonist and/or methylxanthine-treated groups.

Lack of effect of phenobarbital on ex vivo leukocyte oxidative metabolism in healthy volunteers

Oxidative metabolism in activated human polymorphonuclears catabolizes leukotriene B4 by a cytochrome P450 omega-hydroxylase and procainamide by a myeloperoxidase. The percentage of leukotriene B4 metabolized by activated human polymorphonuclears and the apparent enzymatic parameters of procainamide metabolism were studied ex vivo in six healthy volunteers before and after phenobarbital intake (100 mg/day) for 10 days and in six healthy control volunteers. No differences were found between groups for the difference in percentage of leukotriene B4 metabolized between day 11 and day 1. The apparent enzymatic parameters, Km and Vm, of procainamide oxidation did not differ significantly between the groups both on day 1 and day 11. These results do not show any evidence of inducibility of leukotriene B4 and procainamide metabolism in human polymorphonuclears. However, a positive correlation between 6 beta OH-cortisol excretion and percentage of leukotriene B4 metabolized was observed on day 11. This study suggests that human polymorphonuclears cytochrome P450 leukotriene B4 omega-hydroxylase and procainamide metabolism is not a useful method to study cytochrome P450 induction in clinical pharmacology.

Cardiotoxic effects of the combined use of caffeine and isoproterenol in the minipig

Beta agonists such as isoproterenol are widely used in the treatment of acute asthmatic attacks. It would not be unexpected that some patients receiving isoproterenol might have ingested caffeine as an over-the-counter drug or beverage. This study explores the possible interaction between these two drugs. Anesthetized minipigs were injected with 0.5 mg/kg caffeine iv followed by a 10-min infusion of 1 microgram/kg.min isoproterenol. Heart rate, EKG, respiration, and blood pressure were recorded continuously and the animals were sacrificed at 72 h. The two drugs in combination produced subtle changes in heart rate and blood pressure with significant alteration in the EKG tracing (premature ventricular contractions and extrasystoles). These changes persisted for 8 to 24 h. At autopsy both gross and microscopic lesions were noted in 10 of the 13 minipig hearts receiving the combination of drugs. This was not true of the six minipigs given only caffeine or the eight minipigs receiving only the infusion of isoproterenol. No changes in EKG tracings or pathologies were noted with caffeine and only two of eight animals infused with isoproterenol showed any lesions. Results indicate that doses of caffeine equivalent to that expected from drinking a cup of coffee appear to increase the toxicity of isoproterenol to a point that EKG changes and myocardial pathologies are observed.

Protection against isoproterenol-induced myocardial necrosis in rats by 6-mercaptopurine and 6-thioguanine or by irradiation

Isoproterenol produces myocardial necrosis in rats. To investigate the possible role of oxygen free radicals generated by xanthine oxidase and neutrophils, we examined the effects of the xanthine oxidase inhibitors, 6-mercaptopurine (6MP) and 6-thioguanine (6TG) combined and allopurinol, or of irradiation (to induce leukopenia) on isoproterenol-induced myocardial necrosis (ISOMN). The incidence and severity of ISOMN was significantly reduced by 6MP + 6TG but not by the specific inhibitor of xanthine oxidase, allopurinol, indicating that the protective effects of 6MP + 6TG may be due to its free radical scavenging activity rather than its xanthine oxidase inhibitory activity. Irradiation provided complete protection against ISOMN in all rats. Marked leukopenia or other radiation-induced protective factors could play a role in the mechanism of the protection.

Enhanced myocardial necrosis induced in rats by the combined administration of hydralazine and prenalterol

The cardiotoxic effects of hydralazine and prenalterol, given alone and in combination, were assessed in rats and rabbits. Acute myocardial necrosis was induced by a single administration of each drug alone in rats. However, the incidence and severity of lesions were markedly enhanced when both drugs were given in combination. Rats that received the same treatment for 10 consecutive days showed minimal or no acute necrosis, demonstrating the development of a resistance to further cardiotoxic effects of the drugs. Rabbits showed only minimal lesions when either drug was used alone and no enhancement of lesions when they were given in combination. From these data, it is concluded that the possibility of a cardiotoxic interaction exists when these drugs are used in combination and that the heavy rat (500-600 g) is a more sensitive model than the rabbit for studies of this nature.

Ventricular fibrillation threshold and myocardial cyclic AMP production in rats sensitive or resistant to isoproterenol

Beta-Adrenoceptor agonists, such as isoproterenol, produce ventricular fibrillation and myocardial necrosis in rats. After the initial insult, a resistance develops to the lesion-inducing effects of subsequent doses of the drug. Cyclic AMP has been considered to play a major role in beta-adrenergic amine-induced myocardial necrosis as well as in the genesis of ventricular fibrillation. In the present studies, we investigated the ventricular fibrillation threshold and the responsiveness of myocardium to cAMP formation in isoproterenol-sensitive and resistant rats. Myocardial necrosis was induced in male Sprague-Dawley rats by subcutaneous injection of isoproterenol at 50 micrograms/kg for 2 consecutive days to make them resistant to subsequent challenges. Control rats received saline. Both groups were challenged 10 days later with graded doses of isoproterenol and ECGs were recorded. In another experiment, hearts from rats similarly treated were used for histopathology and cAMP determinations. The incidence of ventricular fibrillation and death was significantly lower in resistant rats compared with isoproterenol-sensitive rats. All rats pretreated with isoproterenol showed healed myocardial necrosis. The basal myocardial cAMP levels and the levels after in vitro isoproterenol stimulation were not significantly different between isoproterenol- and saline-pretreated rats. Moreover, no significant differences in the responsiveness of myocardium to cAMP formation were noted between the more sensitive apical and less sensitive ventricular regions in resistant or sensitive rats. These data indicate that the altered myocardial sensitivity or the mechanism for the increased ventricular fibrillation threshold in isoproterenol resistance appears to involve factors other than cAMP.

Determinants of resistance to the cardiotoxicity of isoproterenol in rats

Induction of myocardial necrosis by isoproterenol produces resistance to the necrogenic effects of subsequent doses of the drug. A series of experiments were performed to further define the determinants of resistance. Myocardial necrosis was induced in male Sprague-Dawley rats by sc injection of isoproterenol at 50 micrograms/kg daily for 10 consecutive days or as a single dose at 50, 5, or 0.5 micrograms/kg. These preconditioning doses were followed, at various times, by a challenge dose of 50 micrograms/kg. The rats were killed 48 hr after the challenge dose, and their hearts were analyzed morphometrically to determine the amount of acute necrosis and scarring. The amount of scar tissue was a reflection of necrosis caused by the preconditioning dose whereas acute necrosis reflected response to the challenge dose. Resistance occurred and lasted longer than 19 to 20 weeks after both single or multiple isoproterenol injections of 50 micrograms/kg, but it was not observed 5 days after administration of a single preconditioning dose. Isoproterenol at 0.5 micrograms/kg produced only very minimal or no myocardial necrosis and did not produce resistance. The resistance was not dependent on the size of the area of necrosis produced during the preconditioning period, showing that it was not due to destruction of all vulnerable muscle by the preconditioning dose(s). The preexistence of lesions, however, was necessary for the development of resistance. It is concluded that development of resistance to the necrogenic effects of isoproterenol reflects an adaptive alteration in the myocardium which survives after a necrogenic dose.

Enhancement of cardiotoxic effects of beta-adrenergic bronchodilators by aminophylline in experimental animals

To examine the cardiotoxic interaction between beta-adrenergic bronchodilators and theophylline, we tested the effects of isoproterenol or bitolterol alone and in combinations with aminophylline in experimental animals, both electrocardiographically and histologically. The sc LD50 values for isoproterenol in 4- to 5-month-old, 500-600 g (heavy) and 1.5- to 2-month-old, 150-200 g (small) male Sprague-Dawley rats were 0.6 mg/kg and 1300 mg/kg, respectively, and values for bitolterol were 4 mg/kg and greater than 1800 mg/kg, respectively. Results of the electrocardiographic studies in heavy rats, using the calculated LD20 dosage of isoproterenol with or without pretreatment of aminophylline, demonstrated that both mortality and the arrhythmia-inducing effect of isoproterenol were significantly potentiated by aminophylline but only mortality was increased in small rats. Aminophylline also potentiated the electrocardiographic effects of 1/40 of the LD50 dosage of isoproterenol in heavy rats but did not enhance the effects of bitolterol at this dose level. Potentiation of the arrhythmogenic effect of isoproterenol was also observed in rabbits. The severity of the myocardial lesions produced by isoproterenol or bitolterol in heavy rats was significantly enhanced by aminophylline. The heavy rat appears to be a sensitive model for studying the interaction of these classes of drugs.

Protein degradation in the mouse blastocyst

The degradation characteristics of 56 individual newly synthesized proteins of the Day 4 mouse blastocyst have been examined employing double isotope labeling of proteins for half-life measurement and two-dimensional electrophoresis for separation of proteins. The half-lives ranged from 1 to approximately 30 h with a mean of 12.4 h. Several proteins appeared to have half-lives greater than 30 h but decay times were insufficient to provide precise information for these proteins. The results suggest there is a tendency for proteins with acidic isoelectric points to be degraded more rapidly than basic proteins, and for high molecular weight proteins to be degraded more rapidly than low molecular weight proteins. Although the regressions of these two parameters on half-life were not significant, the direction and magnitude of the trends were similar to those previously described for liver proteins. Two specific proteins, tubulin and actin, were tentatively identified, and their half-lives determined. Tubulin had a half-life of 9.0 h. The half-lives of the provisionally identified gamma, beta, and alpha forms of actin were 2.2, 8.7, and 5.4 h respectively.